The present invention relates to refreshing and data scrubbing of a memory device, and more particularly, to controlling refresh with data scrubbing and refresh without data scrubbing for enhanced data integrity without undue increase of power consumption.
Semiconductor memory devices have been developed to have increasing capacity and speed for use in high-performance electronic systems. For example, a dynamic random access memory (DRAM) is volatile memory that stores data according to an amount of charge stored in a capacitor. Because of leakage of such stored charge with time, a refresh operation for recharging data is performed to prevent loss of data.
Semiconductor memory devices are widely used in mobile devices such as laptop computers, mobile phones, etc. Thus, power consumption of the semiconductor memory devices is desired to be reduced. However, refresh operation of a dynamic memory device such as a DRAM increases standby power consumption. Moreover, the capacitance for storing charge in a DRAM decreases with increased integration of the DRAM resulting in degradation of data reliability.